A Manhattan investor slapped his business partner, celebrity chef Gordon Ramsay, with a $10.8 million lawsuit claiming the famously hot-tempered cook gobbled up profits at their Los Angeles burger joint by treating the eatery like his own fiefdom.

“Gordon Ramsay attempted to run the business and make decisions … similar to his television personality on Hell’s Kitchen — as a dictatorship, without the proper authority and without consent of his partner,” sniffs Rowen Seibel in his new Manhattan civil suit.

Seibel plunked down $800,000 to open Fat Cow with Ramsay in September 2012.

But their 50/50 partnership quickly soured when Ramsay insisted on naming the joint Fat Cow even though he was aware of trademark issues with a Florida restaurant that had rights to the same name in Spanish — Las Vacas Gordas.

He also used his personal interior decorator for the LA space and turned the restaurant into a TV studio for his reality show “Hell’s Kitchen,” the suit says.

Ramsay even told Seibel not to worry about the name, bragging, “Don’t worry, I’m the trademark queen,” according to court papers.

Less than two years after opening, Ramsay announced — without consulting his partner — that he would shutter Fat Cow, citing the trademark problems.

But Seibel believes the reasons for the closing are a lot less appetizing.

“Ramsay fraudulently induced Seibel to invest over $800,000 in Fat Cow Restaurant — an investment that went towards an expensive build-out of the lease space with a new kitchen, new fixtures and furnishings, and to train the restaurant staff — but then intentionally forced Fat Cow Restaurant to close so that he could use Seibel’s investment to benefit another Gordon Ramsay restaurant,” the suit says.

The famed chef now plans to reopen a second eatery in the same location with the same staff called Gordon Ramsay at the Grove or GR Roast — but has cut Seibel out of the business this time, according to court papers.

Seibel, who licenses trademarks from Serendipity 3, wants his investment back plus $10 million in damages for Ramsay’s “egregious misconduct, fraud, self-dealing and theft of corporate opportunity.”

Beside the partnership feud, Fat Cow had a troubled past. The Grove Drive eatery faced a class action lawsuit by staffers over unpaid wages and a $43,000 claim by a contractor for kitchen equipment.

A Ramsay spokeswoman said, “We’re surprised that Mr. Seibel has the audacity to file this ridiculous suit when he and his team were responsible for the day-to-day running of The Fat Cow and spectacularly mismanaged it, resulting in a string of financial and legal issues. Gordon Ramsay and his team immediately stepped in and tried to resolve these issues, but Seibel refused to engage in any meaningful conversations, rendering the restaurant unsustainable.”